Method for placing and trimming packing inserts and the like



March 16, 1965 I J. w. BROWN 3,173,695-

METHOD FOR PLACING AND TRIMMING PACKING INSERTS AND THE LIKE Filed May 29, 1962 3 tsh t 1 FIG.|

INVENTOR JOSEPH W. BROWN W,- AW

ATTORNEY March 16, 1965 J. w. BROWN 3,173,695

METHOD FOR PLACING AND TRIMMING PACKING INSERTS AND THE LIKE Filed May 29, 1962 3 Sheets-Sheet 2 FIG- 2 49 FIG. 3

54 INVENTOR aosspu w. BROWN ATTORNEY March 16, 1965 J. w. BROWN METHOD FOR PLACING AND TRIMMING PACKING INSERTS AND THE LIKE Filed May 29, 1962 3 Sheets-Sheet 3 FIG. 4

FIG. 5 a2 I NVENTOR JOSEPH W. BROWN ATTORNEY United States Patent [mil 4 Unions. (CL 277--l) This application is a division of application Serial No. 198,573, filed May 2 1962, entitled Apparatus for Placing and Trimming Inserts and the Like.

The present invention relates generally to a method for inserting a flexible element into a suitable seat formed in a more or less rigid member; and more particularly to a method for inserting packing into an arcuate seat in a sealing block.

In many mechanical environments, for example in automotive engines, a rotating shaft is provided with a seal formed by two generally similar sealing blocks each having a semi-cylindrical recess grooved over its semicircumference to receive a strip of pack ng or sealing material seated therein but slightly projecting radially therefrom so that when the blocks are secured to each other in opposed relation about the shaft, the sealing material forms a circumferential shaft seal. The sealing material for such a purpose is commonly woven from thick threads of fibrous material into heavy cord-like form and impregnated with solid or viscous lubricants.

By present practice, a sealing material strip of excess length is seated in the groove of the semi-cylindrical surface with excess sealing material projecting from opposite ends of the groove, and the excess at each end is cut away by hand with a knife guided on a surrounding flat surface of the block lying substantially in a plane diametric to the semi-cylindrical surface in the usual block. To obtain an optimum seal, it is necessary that the excess packing material be cut flush at a plane coincident with such surrounding surface of the block, representing an operation which has not as yet been carried out in a practical manner by any acceptable known apparatus.

By the present invention as hereinafter disclosed there is afforded a method for properly seating a packing strip in a seal block as a semi-circular seal element of desired form, the element being of excess length, and thereafter cutting off the excess at the required location, all in a relatively rapid and precise manner. For this purpose, the specifically described apparatus includes a reciprocable working head movable by a pressurized fluid actuated cylinder in a press-like arrangement toward and away from a sealing block on which is positioned a relatively straight strip of the packing material of excess length, the block having a semi-cylindrical portion adapted to carry the strip into a grooved seat therefor on the block, suitably seat and form the sealing material, and then cut off simultaneously two projecting ends of the material at the exact location and plane required.

It is the general object of the present invention to provide a method for properly seating a packing strip in a seal block groove while shaping the same to desired form and thereafter to cut off the sealing material precisely flush with adjacent areas of the seal block structure. An other object of the present invention is to provide a methed for properly inserting, forming and trimming the sealing material for a seal block which obviates manual cutting of the sealing material by an operator.

Other objects and advantages will appear from the following description and the drawings wherein:

FIG. 1 is a front elevational view showing the general arrangement of an apparatus embodying the present invention in its operation;

3,173,695 Patented Mar. 16, 1965 ice FIG. 2 is a detail view of a working head of the apparatus partly in vertical section and with certain portions broken away;

FIG. 3 is a partial plan detail view corresponding to FIG. 2;

FIG. 4 is a vertical section through the working head taken as indicated by the line 44 in FIG. 2;

FIG. 5 is a detail view of a seal block and seal packing shown as an example of workpiece elements operated on by the apparatus; and

FIG. 6 is a fragmentary detail view of the block of FIG. 5.

One manner of carrying out the invention is illustrated by FIGS. 1, 2, 3 and 4 of the drawings showing a machine adapted to carry out the insertion and trimming of a semicircular sealing packing element WP in a groove formed in a semi-cylindrical recess of a seal block WB appearing in FIGS. 5 and 6 as the elements of the work designated W presented to the machine.

As shown in FIG. 1, the principal components of the apparatus are a sturdy bench or table B serving as a base; a roughly C-shaped casting providing a primary frame or pedestal F, having a foot portion 1% secured on base B and a top portion 11 overhanging working space therebelow; a working head H secured on the lower end of a vertical slide member S reciprocable in a slideblock 12 mounted on the frame top 11; a pneumatic cylinder C with piston rod arranged in vertical alignment with the slide member S and having its piston member 13 secured to the upper end of the slide member; an auxiliary frame structure G for rigidly supporting the cylinder unit on the primary frame F; and means M for locating and clarnpin g the work W relative to the base B in proper position for operations thereon by the head H.

Before considering further details of the apparatus, it is noted that the work W upon which the machine operates is here shown as comprised of the seal block WB having a substantially semi-cylindrical recess 30 grooved at 31 to receive a major portion of the thickness of a suitable packing element WP, the groove 31 shown as having side walls inwardly convergent to a flat groove bottom surface. Two such blocks generally of identical form with inserted packing are intended to be brought into opposed relation, with the coplanar surfaces 32 in respectively abutting relation and secured by suitable bolts passed through aligned apertures or bores 33, to provide a circumferential circular or cylindrical seal about a rotating shaft. Hence it is highly important that the packing member WP be inserted evenly to fill the full depth of the groove 31 with a substantially equal radial thickness throughout the resulting semi-circle of packing not received by the groove; and also that thereafter in each block the ends of the packing element be flush with the adjacent surrounding end surfaces 32. This is accomplished in the disclosed apparatus by the head H which suitably seats a packing element of excess length in the groove with ends 3d (see FIG. 5) projecting above a respective adjacent surface and thereafter cuts off the projecting ends by respective knife blades sliding with cutting edges in the plane of surfaces 32.

In the frame G, a horizontal plate member 15, secured on the top portion 11 through depending members 16 embracing opposite sides of the head 11, has rigidly secured thereto four spaced vertical post members 18 on the top of which is secured a plate 19 supporting the lower end of the cylinder unit C and to which in turn in spaced parallel relation a fiat horizontal plate member 20 is secured through tie bolts 21 to provide a reaction surface for the upper end of the cylinder C.

The cylinder C is preferably a double-acting piston cylinder unit to the opposite ends of which pressurized operating fluid is supplied as required from a controlled 3 M supply source (not shown) through conduits 24 and 25 at the upper and lower cylinder ends respectively. The slide member S and the slide receiving aperture in the edoperating slidebloek or slideway member 12 preferably have some non-circular cross section being for example rectangular, with an appropriate non-rotatable connection between the slideand head Hto guide the head vertical reciprocation without any twisting.

Inthe operating head, H, of generally symmetrical structure about a verticalcenterline or plane (see .FIG.

;2), a rectangular body element or block 4% is secured smaller than and .dilfering from the radius of the semicircular recessSt) of the intended work by substantially the amount of the desired radial projection of the packing WPinserted in the groove 30; and at opposite sides ofthe pro ection 40a, the lower end of the body is further providedwith coplanar end surfaces 43!; lying in a ,diametral plane of and at the base of the projection the.

iThe thickness of the portion 40a preferably is somewhat greater than the width of the groove 34 and the packing to be inserted therein to provide a semi-cylindrical; surface beyond the ends of which the packing WP I willnot escape undeninsertion pressures forming the shaft-engaging surface thereof. I

.1; As may be better seen from FIG. 4 taken in conjunctiodwith FIG. 2,- a slideway 400 for identical knife ear ers 45 actuated by cylinders 48 is cut through the .ubldck- 40 parallel to the surfaces 4% and therefore to the base dia'rtletral plane of the projection 40a. The

..slideway issomew'hatT-shaped in form having an upper 'wportiongsquare in'cross-section and a lower portion of --smallerwidthopening through the face of Surfaces 40b; 1 and in thezregion of the projection 40a has a bottom wall or. surface coplanar, with surfaces 40b.

The .kliife carrying .slideblocks 45 have main body portions 45a complementary in cross-section to and slidable iii the square portion of the slideway 40c, andnear theii inner ends downward projections 45b to which the knife blades 46 are. secured,-removably for replacement or'sharpening, by. flat head screws 52. The joint crosssection of projections 45b and knives 46 is generally complementary to the lower. portion of the slideway 40c into which theyare received. Hence, abutment of the surfaces 40b on the surfaces 32 of a block assures an exact-positioning and guiding of the knife edges relative to the surfaces 32; for as will be noted, the cutting edge 46a of a knife 46 is formed between an upper bevel and a straight bottom blade face, and therefore the actual cutting edge is movable substantially in the plane of the surfaces 40b.

. .Outward beyond the knife supporting projection there is provided clearance for a projecting end of the packing, as at 35 inFIG. 5, and also between the carrier block and the projecting cutting edge portion of the knife. As appears in FIG. 2, the length of the knife blade and the innermostpositioning of the knife carrier blocks 45 is suchthat the cutting edge of the knife is completely retracted within the limits of the diameter 40a.

'For knife reciprocation, the blocks 45 are threaded on aligned piston rods 47 of the piston-cylinder units 48 secured onopposite sides of block 40 through mounting-means including L-shaped mounting blocks 49 attached to opposite side faces of block 40 by cap screws a For each-cylinder unit 48, additional structure is in- 'cludedsQmeWhQtsimiIar to that for the main press power cylinder C, including a member 54 affixed to or integral with the L-shaped member 49, providing a seat for one end of the cylinder and apertured for the piston rod 47 projecting therethrough, and a second member 55 secured in spaced relation to 5'4 by tie bolts as, so that the cyl- .inder is. embraced endwise between the members 54 and 55.

The cylinder units.48 may be double-acting as here shown with pressurized fluid selectivelyapplied to opposite ends through conduits 6. 1, 62 for drawing the knives outwardly a cutting stroke and returning them to endwise or retracted position respectively, or the units may be single-acting to be moved. in the cutting stroke by fluid pressure but spring-returned upon release of the cutting pressure.

The means M for properly locating a block WB relative to the path of the head 45) as each block is manually or otherwise placed in position, although here shown in generalized form, may be any suitable means known to the art providing at least surfaces for locating a front or back face of the block and one end of the block; and further, if desired or convenient, for clamping the block .WB in the required position either by fluid pressure cylinders or mechanical means as well known for such purpose.

In carrying out the work assembly, the block is properly positioned, and a straight piece of the packing of suitable length is laid across the top of the block on the sufaces 32 as indicated in FIG. 5, and positioned in alignment with the open ends of the groove 31. Then through suitable controls pressure is applied at 24 to cylinder C to move the head downwardly, the projection 46' encountering and carrying the packing strip downwardly and forming it radially into the groove 31, until the flat surfaces 40b at the bottom of the head block 49 engage the top surfaces 32 of the workpiece block, thereby bringing the plane of knife edge lateral movement substantially to the plane of surfaces 32. Fluid pressure is then applied to the cylinders 48 simultaneously to move the blades outwardly away from each other thereby severing the projecting ends of the packing perfectly flush with the surfaces 32. Thereupon the cutting pressure isreleased, and the knives thereafter returned either by spring action in the case of a springreturned type unit, or by return fluid pressure applied at conduit 62; whereupon the head may be retracted or raised upon release of pressure at 24 by work head returning pressure at 25. With appropriate regulation of air pressure supplied to cylinder C, the end surfaces 32 of the block WB itself may provide suitable stop means for the working head determining the final position of arcuate projection a relative to the packing seat groove.

Since various types of pneumatic or hydraulic fluid pressure supply systems and operating controls may be used as well known in the art, and these would vary with the particular conveniences of operation desired, and types of cylinder units, and would depend in part on whether the machine is manually fed and operator actuated for each step of the method, or automatically fed and operated, and further the details of such control are not per se part of the invention, these are here no further related. However, a pneumatic system is generally preferred because of simplicity and generally lower initial and maintenance costs.

I claim:

1.In the manufacture of a relatively rigid member having at one edge a concave recess with a surface of no greater circumferential extent than a semi-cylinder, a circumferentially extending seat groove in said surface with opposite ends opening at said edge through flat edge surfaces, and a fiexible element of elongated material seated in said groove and having opposite ends terminating flush with said flat surfaces, the method of assembling said member and element comprising; placing an excess length of the material on said edge in the plane of said groove; engaging said length with a forming element having a convex surface of curvature which may be brought into parallelism with the concave surface; moving the forming element into said recess while maintaining said engagement until such parallelism is obtained thereby to seat said flexible element in the groove With opposite ends projecting therefrom and to form its exposed surface to the shape of the convex surface; and cutting the projection ends each flush with a respective said flat surface by blades guided in said forming member to move With cutting edges substantially in the planes of respective fiat surfaces.

2. A method as set forth in claim 1, wherein said flexible element is seated before said parallelism is attained thereby forming the same to project from said groove.

3. In the manufacture of a shaft seal block having at one fiat edge a semi-cylindrical concave recess, a circumfercntially extending seat groove in said recess with opposite ends opening through said fiat edge and a flexible sealing element of elongated packing material seated in but projecting radially from said groove and having opposite ends terminating flush with said edge, the method of assembling said element in the block comprising: placing an excess length of the material on said edge in the plane of the groove; engaging said length with a forming element having a semi-cylindrical surface of curvature which may be brought into parallelism with an spaced from the recess surface; moving the forming element into said recess While maintaining said engagement until such parallelism is obtained thereby to seat said flexible element in the groove with opposite ends projecting therefrom and to form its exposed surface to a semi-cylindrical shape, and cutting the projecting ends each flush with the adjacent fiat suface of said edge by blades guided in said forming member to move with cutting edges substantially in the plane of said edge.

4. A method as set forth in claim 3 wherein said flexible element is seated before said parallelism is attained thereby forming the same with a semi-cylindrical convex surface spaced from the surface of said recess.

N 0 references cited.

WHITMORE A. VVlLTZ, Primary Examiner. 

1. IN THE MANUFACTURE OF A RELATIVELY RIGID MEMBER HAVING AT ONE EDGE A CONCAVE RECESS WITH A SURFACE OF NO GREATER CIRCUMFERENTIAL EXTENT THAN A SEMI-CYLINDER, A CIRCUMFERENTIALLY EXTENDING SEAT GROOVE IN SAID SURFACE WITH OPPOSITE ENDS OPENING AT SAID EDGE THROUGH FLAT EDGE SURFACES, AND A FLEXIBLE ELEMENT OF ELONGATED MATERIAL SEATED IN SAID GROOVE AND HAVING OPPOSITE ENDS TERMINATING FLUSH WITH SAID FLAT SURFACES, THE METHOD OF ASSEMBLING SAID MEMBER AND ELEMENT COMPRISING; PLACING AN EXCESS LENGTH OF THE MATERIAL ON SAID EDGE IN THE PLANE OF SAID GROOVE; ENGAGING SAID LENGTH WITH A FORMING ELEMENT HAVING A CONVEX SURFACE OF CURVATURE WHICH MAY BE BROUGHT INTO PARALLELISM WITH THE CONCAVE SURFACE; MOVING THE FORMING ELEMENT INTO SAID RECESS WHILE MAINTAINING SAID ENGAGEMENT UNTIL SUCH PARALLELISM IS OBTAINED THEREBY TO SEAT SAID FLEXIBLE ELEMENT IN THE GROOVE WITH OPPOSITE ENDS PROJECTING THEREFROM AND TO FORM ITS EXPOSED SURFACE TO THE SHAPE OF THE CONVEX SURFACE; AND CUTTING THE PROJECTION ENDS EACH FLUSH WITH A RESPECTIVE SAID FLAT SURFACE BY BLADES GUIDED IN SAID FORMING MEMBER TO MOVE WITH CUTTING EDGES SUBSTANTIALLY IN THE PLANES OF RESPECTIVE FLAT SURFACES. 